From 0377ad93031d3e51c2afe44231241185f684b6af Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C3=81lvaro=20Fern=C3=A1ndez=20Rojas?= <noltari@gmail.com>
Date: Fri, 5 Mar 2021 15:14:32 +0100
Subject: [PATCH] mips: bmips: automatically detect CPU frequency
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Some BCM63xx SoCs support multiple CPU frequencies depending on HW config.

Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
---
 arch/mips/bmips/setup.c | 197 ++++++++++++++++++++++++++++++++++++++--
 1 file changed, 190 insertions(+), 7 deletions(-)

--- a/arch/mips/bmips/setup.c
+++ b/arch/mips/bmips/setup.c
@@ -32,13 +32,52 @@
 
 #define RELO_NORMAL_VEC		BIT(18)
 
+#define REG_BCM6318_SOB		((void __iomem *)CKSEG1ADDR(0x10000900))
+#define BCM6318_FREQ_SHIFT	23
+#define BCM6318_FREQ_MASK	(0x3 << BCM6318_FREQ_SHIFT)
+
 #define REG_BCM6328_OTP		((void __iomem *)CKSEG1ADDR(0x1000062c))
 #define BCM6328_TP1_DISABLED	BIT(9)
+#define REG_BCM6328_MISC_SB	((void __iomem *)CKSEG1ADDR(0x10001a40))
+#define BCM6328_FCVO_SHIFT	7
+#define BCM6328_FCVO_MASK	(0x1f << BCM6328_FCVO_SHIFT)
+
+#define REG_BCM6358_DDR_PLLC	((void __iomem *)0xfffe12b8)
+#define BCM6358_PLLC_M1_SHIFT	0
+#define BCM6358_PLLC_M1_MASK	(0xff << BCM6358_PLLC_M1_SHIFT)
+#define BCM6358_PLLC_N1_SHIFT	23
+#define BCM6358_PLLC_N1_MASK	(0x3f << BCM6358_PLLC_N1_SHIFT)
+#define BCM6358_PLLC_N2_SHIFT	29
+#define BCM6358_PLLC_N2_MASK	(0x7 << BCM6358_PLLC_N2_SHIFT)
+
+#define REG_BCM6362_MISC_SB	((void __iomem *)CKSEG1ADDR(0x10001814))
+#define BCM6362_FCVO_SHIFT	1
+#define BCM6362_FCVO_MASK	(0x1f << BCM6362_FCVO_SHIFT)
+
+#define REG_BCM6368_DDR_PLLC	((void __iomem *)CKSEG1ADDR(0x100012a0))
+#define BCM6368_PLLC_P1_SHIFT	0
+#define BCM6368_PLLC_P1_MASK	(0xf << BCM6368_PLLC_P1_SHIFT)
+#define BCM6368_PLLC_P2_SHIFT	4
+#define BCM6368_PLLC_P2_MASK	(0xf << BCM6368_PLLC_P2_SHIFT)
+#define BCM6368_PLLC_NDIV_SHIFT	16
+#define BCM6368_PLLC_NDIV_MASK	(0x1ff << BCM6368_PLLC_NDIV_SHIFT)
+#define REG_BCM6368_DDR_PLLD	((void __iomem *)CKSEG1ADDR(0x100012a4))
+#define BCM6368_PLLD_MDIV_SHIFT	0
+#define BCM6368_PLLD_MDIV_MASK	(0xff << BCM6368_PLLD_MDIV_SHIFT)
+
+#define REG_BCM63268_MISC_SB	((void __iomem *)CKSEG1ADDR(0x10001814))
+#define BCM63268_FCVO_SHIFT	21
+#define BCM63268_FCVO_MASK	(0xf << BCM63268_FCVO_SHIFT)
 
 extern bool bmips_rac_flush_disable;
 
 static const unsigned long kbase = VMLINUX_LOAD_ADDRESS & 0xfff00000;
 
+struct bmips_cpufreq {
+	const char		*compatible;
+	u32			(*cpu_freq)(void);
+};
+
 struct bmips_quirk {
 	const char		*compatible;
 	void			(*quirk_fn)(void);
@@ -154,17 +193,161 @@ const char *get_system_type(void)
 	return "Generic BMIPS kernel";
 }
 
+static u32 bcm6318_cpufreq(void)
+{
+	u32 val = __raw_readl(REG_BCM6318_SOB);
+
+	switch ((val & BCM6318_FREQ_MASK) >> BCM6318_FREQ_SHIFT) {
+	case 0:
+		return 166000000;
+	case 2:
+		return 250000000;
+	case 3:
+		return 333000000;
+	case 1:
+		return 400000000;
+	default:
+		return 0;
+	}
+}
+
+static u32 bcm6328_cpufreq(void)
+{
+	u32 val = __raw_readl(REG_BCM6328_MISC_SB);
+
+	switch ((val & BCM6328_FCVO_MASK) >> BCM6328_FCVO_SHIFT) {
+	case 0x12:
+	case 0x14:
+	case 0x19:
+		return 160000000;
+	case 0x1c:
+		return 192000000;
+	case 0x13:
+	case 0x15:
+		return 200000000;
+	case 0x1a:
+		return 384000000;
+	case 0x16:
+		return 400000000;
+	default:
+		return 320000000;
+	}
+}
+
+static u32 bcm6358_cpufreq(void)
+{
+	u32 val, n1, n2, m1;
+
+	val = __raw_readl(REG_BCM6358_DDR_PLLC);
+	n1 = (val & BCM6358_PLLC_N1_MASK) >> BCM6358_PLLC_N1_SHIFT;
+	n2 = (val & BCM6358_PLLC_N2_MASK) >> BCM6358_PLLC_N2_SHIFT;
+	m1 = (val & BCM6358_PLLC_M1_MASK) >> BCM6358_PLLC_M1_SHIFT;
+
+	return (16 * 1000000 * n1 * n2) / m1;
+}
+
+static u32 bcm6362_cpufreq(void)
+{
+	u32 val = __raw_readl(REG_BCM6362_MISC_SB);
+
+	switch ((val & BCM6362_FCVO_MASK) >> BCM6362_FCVO_SHIFT) {
+	case 0x04:
+	case 0x0c:
+	case 0x14:
+	case 0x1c:
+		return 160000000;
+	case 0x15:
+	case 0x1d:
+		return 200000000;
+	case 0x03:
+	case 0x0b:
+	case 0x13:
+	case 0x1b:
+		return 240000000;
+	case 0x07:
+	case 0x17:
+		return 384000000;
+	case 0x05:
+	case 0x0e:
+	case 0x16:
+	case 0x1e:
+	case 0x1f:
+		return 400000000;
+	case 0x06:
+		return 440000000;
+	default:
+		return 320000000;
+	}
+}
+
+static u32 bcm6368_cpufreq(void)
+{
+	u32 val, p1, p2, ndiv, m1;
+
+	val = __raw_readl(REG_BCM6368_DDR_PLLC);
+	p1 = (val & BCM6368_PLLC_P1_MASK) >> BCM6368_PLLC_P1_SHIFT;
+	p2 = (val & BCM6368_PLLC_P2_MASK) >> BCM6368_PLLC_P2_SHIFT;
+	ndiv = (val & BCM6368_PLLC_NDIV_MASK) >>
+	       BCM6368_PLLC_NDIV_SHIFT;
+
+	val = __raw_readl(REG_BCM6368_DDR_PLLD);
+	m1 = (val & BCM6368_PLLD_MDIV_MASK) >> BCM6368_PLLD_MDIV_SHIFT;
+
+	return (((64 * 1000000) / p1) * p2 * ndiv) / m1;
+}
+
+static u32 bcm63268_cpufreq(void)
+{
+	u32 val = __raw_readl(REG_BCM63268_MISC_SB);
+
+	switch ((val & BCM63268_FCVO_MASK) >> BCM63268_FCVO_SHIFT) {
+	case 0x3:
+	case 0xe:
+		return 320000000;
+	case 0xa:
+		return 333000000;
+	case 0x2:
+	case 0xb:
+	case 0xf:
+		return 400000000;
+	default:
+		return 0;
+	}
+}
+
+static const struct bmips_cpufreq bmips_cpufreq_list[] = {
+	{ "brcm,bcm6318", &bcm6318_cpufreq },
+	{ "brcm,bcm6328", &bcm6328_cpufreq },
+	{ "brcm,bcm6358", &bcm6358_cpufreq },
+	{ "brcm,bcm6362", &bcm6362_cpufreq },
+	{ "brcm,bcm6368", &bcm6368_cpufreq },
+	{ "brcm,bcm63268", &bcm63268_cpufreq },
+	{ /* sentinel */ }
+};
+
 void __init plat_time_init(void)
 {
+	const struct bmips_cpufreq *cf;
 	struct device_node *np;
-	u32 freq;
+	u32 freq = 0;
 
-	np = of_find_node_by_name(NULL, "cpus");
-	if (!np)
-		panic("missing 'cpus' DT node");
-	if (of_property_read_u32(np, "mips-hpt-frequency", &freq) < 0)
-		panic("missing 'mips-hpt-frequency' property");
-	of_node_put(np);
+	for (cf = bmips_cpufreq_list; cf->cpu_freq; cf++) {
+		if (of_flat_dt_is_compatible(of_get_flat_dt_root(),
+					     cf->compatible)) {
+			freq = cf->cpu_freq() / 2;
+			printk("%s detected @ %u MHz\n", cf->compatible, freq / 500000);
+			break;
+		}
+	}
+
+	if (!freq) {
+		np = of_find_node_by_name(NULL, "cpus");
+		if (!np)
+			panic("missing 'cpus' DT node");
+		if (of_property_read_u32(np, "mips-hpt-frequency", &freq) < 0)
+			panic("missing 'mips-hpt-frequency' property");
+		of_node_put(np);
+	}
 
 	mips_hpt_frequency = freq;
 }
